Nowadays, companies are facing a rapidly changing environment. New products have to be integrated into established manufacturing processes at ever shorter intervals. To assure competitiveness the design of changeable production systems gains more and more importance. Therefore, a control loop of changeability has been developed within the research project “change-supporting process architectures”. The control loop empowers companies to identify urgent changeability needs with an evaluation method and helps them to design and use change-supporting process architectures with economical solutions. The presented article focuses on the methodology for the evaluation of changeability.